Position determining system

Abstract

The present invention is directed to a position determining system ( 100 ) of reduced errors in measurements and determination of surfaces even if a rotary light source emitting laser beam rotates unevenly. The position determining system is comprised of a rotary light source rotating and emitting laser beams (b 1, b 2, b 3 ), an encoder detecting a rotation position of the rotary light source, and a transfer means transmitting data detected by the encoder, and the system particularly comprises at least two rotary laser devices ( 151, 152 ) disposed separate from each other, a light sensor ( 154 ) having a light receiving unit that receives the laser beams emitted from the rotary laser devices, so that a position of the light sensor is determined depending upon the laser beams incident upon the light receiving unit and information transmitted by the transfer means.

What is claimed is:  
     
         1 . A position determining system comprised of a rotary light source rotating and emitting laser beams, an encoder detecting a rotation position of the rotary light source, and a transfer means transmitting data detected by the encoder, the system comprising 
 at least two rotary laser devices disposed separate from each other,    a light sensor having a light receiving unit that receives the laser beams emitted from the rotary laser devices, and    an operational unit using output from the light receiving unit to arithmetically compute a position of the light sensor.    
     
     
         2 . A position determining system according to  claim 1 , wherein the laser beams emitted from the rotary laser devices are diverging laser beams that permit subsequent computations of elevation- or depression-angles.  
     
     
         3 . A position determining system according to  claim 1  or  claim 2 , wherein the transfer means transmitting data from the encoder to the light sensor is an optical communication.  
     
     
         4 . A position determining system according to  claim 1  or  claim 2 , wherein the transfer means transmitting data from the encoder to the light sensor is a communication through electric waves.  
     
     
         5 . A position determining system according to  claim 3 , wherein the light receiving unit (or units) may be shared between a use for the laser beams in detecting the elevation- or depression-angle of the light sensor and a use for the optical communication.  
     
     
         6 . A position determining system according to  claim 1 , wherein substantially two of the laser beams are emitted from the rotary light source.  
     
     
         7 . A position determining system according to  claim 1 , wherein substantially three of the laser beams are emitted from the rotary light source.  
     
     
         8 . A position determining system according to any of  claim 1  to  claim 3 , wherein the light receiving unit of the light sensor has a light converging means.  
     
     
         9 . A position determining system according to  claim 3 , wherein the transfer means for the optical communication may signal by modulating the rotating laser beams.  
     
     
         10 . A position determining system according to any of  claim 1  to  claim 9 , wherein the rotary laser devices have their respective reflecting means reflecting the laser beams emitted from the rotary light source, and light receiving means receiving the beams reflected from the reflecting means, and a rotational reference position of the rotary light source is determined depending upon the timing detected by the light receiving means.  
     
     
         11 . A position determining system according to any of  claim 1  to  claim 9 , wherein the rotary laser devices have their respective light receiving means and light emitting means, and a signal is transmitted from the light emitting means to the light sensor when the diverging laser beams emitted from the rotary laser devices fall on the light receiving means.